LymphoSign Journal

Volume 5 • Number 4 • December 2018

Review

Update on effects of cleaning agents on allergy and asthma

Vol. 5No. 4pp. 121–129

Background: Cleaning and disinfecting agents are widely used in modern life, in homes, schools, public places, and workplaces as well as in recreational facilities such as swimming pools. Use has been for sanitizing purposes and to assist in reduction of infection as well as for deodorizing purposes. However, adverse respiratory effects have been associated with use of cleaning products ranging from effects in infancy and early childhood up to adults at home and work.Methods: This review summarizes recent published literature on the effects of cleaning agents used pre-natally, in childhood and adult life, at home, work, and in swimming pools.Results: Several studies have indicated that there is an increased risk of developing asthma among adults with frequent exposure to cleaning products at work and in the home. Potential mechanisms include sensitization and respiratory irritant effects. Exposure to irritant chlorine by-products from swimming pools have also been associated with respiratory effects and increased risk of asthma. Potential effects from maternal exposures to cleaning products on infants, and effects on early childhood atopy are less clear.Conclusions: Exposure to cleaning agents increases relative risks of asthma among workers, and adults using these agents in the home. Risks are also increased with exposure to chlorinated by-products from swimming pools, both in adults and children. Further studies are needed to understand the mechanisms of these associations.

Novel mutation

Interleukin-2 receptor common gamma chain (IL2RG) defects present a diagnostic challenge

Vol. 5No. 4pp. 130–134

Background: The protein encoded by interleukin-2 receptor common gamma chain (IL2RG) is an important signaling component of many interleukin receptors, including those of interleukin-2, -4, -7, and -21, known as the common gamma chain. Mutations in the gene encoding the common gamma chain of the interleukin-2 receptor cause X-linked severe combined immunodeficiency (SCID). In this report, we present an unknown genetic defect of a patient diagnosed with SCID whose genetic analysis was performed 2 decades later.Methods: Whole genome sequencing and Sanger confirmation were used to identify a novel frameshift mutation in IL2RG. Massively parallel sequencing of genes associated with SCID were performed on the patient’s mother and sister.Results: Next generation sequencing techniques identified a heterozygous frame-shift deletion in the gene encoding the common gamma chain of IL2RG in our patient. The patient’s mother had a low level mosaicism for the same deletion. The sister had no detectable deletion.Conclusion: We have identified a novel mutation in IL2RG resulting in an X-linked SCID phenotype. The genetic analysis of the patient’s mother revealed a mosaicism which was not passed on to his sister. The importance of genetic analysis in family members and SCID patients with an unknown genetic defect should be emphasized for family planning and subsequent genetic counseling.Statement of novelty: Genetic testing is an extremely important component in evaluating severe combined immunodeficiency as it impacts treatment course and prognosis, and allows for genetic analysis and counselling of family members.

A novel homozygous mutation in CIITA resulting in MHC Class II deficiency in an adult patient

Vol. 5No. 4pp. 135–140

Introduction: Major histocompatibility (MHC) class II deficiency is a rare autosomal recessive primary immunodeficiency with fewer than 200 patients reported worldwide. Patients usually present within their first year of life with severe and recurrent infections, failure to thrive, and chronic diarrhea. The disorder is caused by absent or reduced MHC class II expression on cell surfaces, leading to defective cellular and humoral immune responses. The disease is associated with a poor prognosis, with most patients dying in early childhood due to infectious complications.Aim: To report the clinical, immunological, and genetic features of an adult patient with MHC class II deficiency who did not undergo hematopoietic stem cell transplant (HSCT). We also explore proposed theories as to why some patients with MHC class II deficiency survive to adulthood, beyond the typical life expectancy.Results: We present a 23-year-old gentleman who was diagnosed with MHC class II deficiency at the age of 6 months based on a near complete absence of Human Leukocyte Antigen - DR isotype on peripheral blood mononuclear cells and CD4+ lymphopenia. He is one of a few patients with the condition reported in the literature to have survived to adulthood despite not having undergone HSCT. Next generation sequencing revealed a novel homozygous mutation in the CIITA gene, 1 of 4 genes involved in the regulation of MHC class II transcription.Discussion: MHC class II deficiency is considered a single entity phenotypic condition where the main problem lies in reduced or absent MHC class II expression and results in downstream immunologic effects, including CD4+ lymphopenia and impaired antigen specific responses. However, phenotypic differences between patients are emerging as more cases are described in the literature. Our patient, now 23 years old, has survived significantly beyond life expectancy despite not having HSCT.Statement of novelty: We describe a case of an adult patient diagnosed with MHC class II deficiency due to a novel homozygous intronic splice site variant in the CIITA gene.